A machine entity determined to defeat Spartan (and by extension, the Sentinels), the PL 11 Nekrotron evolved from a computer virus brought to life through mystic Lemurian super-science. First created by the villainous Grand Emperor in an effort to destroy Spartan's technologic advantage, Nekrotron has long since outgrown his original programming and form. When one body is defeated, he simply uses a back-up program to create a new body, making him one of the most persistent foes in existence.